Detection of telomerase activity in esophageal squamous cell carcinoma and normal esophageal epithelium

Background/aims: Relatively little has been reported about the telomerase activity of esophageal squamous cell carcinoma or normal esophageal epithelium. In this study, we have evaluated whether telomerase activity is a useful marker for detecting malignancies in the esophagus. Patients/methods: Esophageal carcinomas and normal esophageal tissues adjacent to carcinomas were obtained from 52 surgically treated, unselected patients, and normal esophageal epithelium from 11 non-cancerous patients were obtained by means of biopsy. The telomeric repeat amplification protocol (TRAP) assay was used for detection of telomerase activity in these samples. The incidence of detection of telomerase activity in esophageal carcinoma was compared with that of telomerase activity in normal esophageal epithelium. Moreover, the clinicopathological characteristics of telomerase-positive tumors were compared with those of telomerase-negative tumors. Results: Of the 52 carcinomas, 40 (77%) had detectable telomerase activity. However, telomerase activity was detected in 45 of 52 (87%) normal tissue samples adjacent to carcinomas and in 8 of 11 (73%) normal esophageal epithelium from non-cancerous patients. In esophageal cancer, no significant difference was detected in the clinicopathological findings between the telomerase-positive and -negative cases. Conclusion: These results indicate that not only esophageal squamous cell carcinomas but also normal esophageal epithelium show strong telomerase activity. Thus, telomerase activity may not be a good marker for the detection of carcinoma in the esophagus. Received: 16 March 1999 Accepted: 8 July 1999